Conventionally, as a protective tube for a cable, a metal tube, such as a steel tube and an aluminum tube, and a plastic corrugated tube are used. When using such a tube, there might be a problem such as an influence of noise generated from a cable that is accommodated in the protective tube and an influence of noise from an outside, which affects the internal cable. For example, in a hybrid car, it is necessary to protect a cable that supplies a three-phase alternating current output from an inverter device to a drive motor. Accordingly, a protective tube is arranged, such as on a bottom portion of a body of the car, according to the shape of the body. In this process, because the cable generates noise that is heard in a radio or the like, it is necessary to prepare shielding.
As such a protective tube, there is a tube made of metal, of which the outermost layer is made of stainless-steel and the other layers are made of iron in order to improve endurance (patent document 1).
Furthermore, as a plastic corrugated tube, there is a corrugated tube of which the metal layer is formed by plating (patent document 2).